Grating



NOV. 25, 1930. MlCHELMAN 1,782,789

GRA'I'ING Filed NOV. 30, 1928 Fgii' r- WHW 11v VENTOR M277, cu; (6-6 917114.11. B Y

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ATTORN provision of a novel grating construction Patented Nov. 25, 193.0

UNITED STATES NATHAN MICHELMAN,OFJIB ROOKLY1, ivEw-Yoair eimmnve r Application filed. November 30,1928. Serial N... 322,651.

My invention relates to improvements in gratings, particularly jail door and window gratings and the like, and it is the principal object of. my invention to provide a grating construction which can be readily assem' bled and which is comparatively tool-proof and cannot be readily cut or drilled or otherwise tampered with or removed.

Another object of my invention is the readily manufactured from hardened and tempered chrome or otherwise tough or cohesive material the bars of which are readily and firmly locked in place.

A further object of my invention is the provision of a jail grating provided with meansfor firmly locking the cross and vertical bars in their adjusted and locked position without showing traces of the manner in which the several series of bars are interlocked at their points of intersection."

These and other objects and advantages of my invention will become more fully apparent as the description thereof proceeds and will then be specifically defined in the appended claims. In the accompanying drawing forming a material part of this disclosure:

Fig.1 is a fragmentary front elevation of a grating constructed according to my invention. i

Fig. 2is a detail top view of one of the cross bars of the grating before'the introduction of the vertical bars into the vholes of such bars.

' Fig. 3 is a section on line 3-3 of Fig.

ure 2.

Fig. 4 is a view similar to Figure 2, but

0 showing the manner ofintroducing the vertical bars.

. Fig. 5 is a ure 4:.

Fig. 6 is a fragmentary front elevation of one of the vertical bars of the grating.

As illustrated, the grating according to my invention, like most gratings, consists of a series of parallel vertical bars 10 and a series of horizontal bars 11, preferably arranged at right angles to each other.

section on line 55 of Fig- .sectiom'preferably circular. 5 of simple and comparatively inexpensive tempered steel so as to make them tool-proof, and may have any desired, suitable cross- Thehorizontal or transverse bars are each provided; with a plurality of openings 1 .12 allowing the passage of the verticalbars, andeach of said openings is equipped with an inner groove13 ending ina recess 14. in communication with the opening .12. -The'vertical bars have'each at a suitable point corresponding to the location of the cross-bars protuberances or knobs 15 adapted to fit into the recess 14; and inner .groove 13.

The operation of my device willbeentirely clear from the above description and it will be.clear.that in assembling the bars of the Thesebars are preferably made of'hardened grating, the horizontal bars 11 are first placed at suitable distances apart, and then the vertical bars 10 are passed through the open ings 12in thetransverse bars until their knobs 15 are in position to engage the recesses 1 If new the vertical bars are rotated for about 90 around theirlongitudinal axis their knobs 15 will slide in the'grooves and firmly connectv vertical and horizontal bars. If now the recesses 14 are closed by a wire or the like suitable material 16, inserted into grooves 13 011 the underside of horizontal bars ,11 through recesses 14 and cut ofi,the

and constitute a solid grating which, being of hardened preferably chrome steel cannot be readily cut or drilled and if set between the sill and top of a window, or floor and ceiling of a room cannot readilybe removed.

It will be understood that I have described and shownthepreferredform of my invention as example only of the many. possible so grating will present a finished appearance horizontal bars, each having a plurality of openings in spaced relation, an inner groove formed in said openings, and a peripheral recess formed in the Wall of each opening in communication With said groove, a series of vertical bars, a plurality of protuberances on each of said vertical bars adapted to be entered into the recesses of said horizontal bar openings and to be rotated in the groove thereof, and a Wire entered into said recess to lock the vertical and horizontal bars at their points of intersection.

2. A grating comprising a plurality of series of intersecting horizontal and vertical bars, each of said horizontal bars formed with a plurality of juxtaposed openings allowing the passage of the vertical bars, the Walls forming said openings having an inner groove formed therewith, and said horizontal bars having formed therein recesses in communication with said openings and grooves, a plurality of knobs on each ofsaid vertical bars adapted to enter said recesses and grooves and to slide in the latter upon the rotation of said vertical bars about their longitudinal axes, and Wires entered into said recesses to lock said vertical bars and horizontal bars in their relative adjusted positions.

Si ned at Brooklyn, in the county of Kings and tate of New York, this 23rd day of November, A. D. 1928.

NATHAN MICHELMAN. 

